Cloth cutting machine



Dec. 19, 1933. w. BANGSER CLOTH CUTTING MACHINE Filed Jan. 14, 1931 INVENTOR 50m, ATTO R N EYS Patented Dec. 19, 1933 UNITED STATES v 1,940,483 T O CE l 1,940,483 r CLOTH CUTTING MACHINE w a William Bangser, New York, N. Y.,- assignor to 11.. Maimin Company, Incorporated, a corporation of New York I Application January 14, 1931. 'Serial nasoacss ,14. Claims. (01. 164

This invention relatesto clothrcutting ma chines of the reciprocatingfknifc type and has for its object the provision'of means for oscillating the reciprocating knife during the cutting operation so that the cloth scut with a pinked or scalloped edge' Portable cloth-cutting machines urine recipposition and prevent upward movement which might otherwise be occasioned by the recipro.

cation of the knife. The base plate is provided with rollers which enablethei,operatorto move the machine over the work table by means of a handle fixed to and extending rearwardly from the upper end of the standard. I

It is well recognized thatfor most efiicient cuttingthe motor, knife, knife guide, presser.-foot and throat plate must be nicely adjusted with.

guide, the slotted throat plate and the presserfoot remains unchanged during the cutting operation, although with reference to the standard and base plate and to the cloth, the knife is oscillating.

The form of the pinked or scalloped edge produced by a machine of this type depends upon two factors-the period of oscillation of the knife and the rate of movement of the machine relative to the cloth. Thus, fora" given period of oscillation the number of scallops perinch will depend directly upon the rate at which the operator moves his machine, and as this rate is never uniform, the character of the pinking itself will not be uniform. According to the present inventionmeans are provided for varying the period of oscillation with respect to the ratejof movement of the machine relative to the 9101711. I do this preferably by oscillating the knife by means of the rollers which vsupportthemachine, the period of oscillation thus varying directly with the speed of the machine.

. A better understanding or the invention will be obtained from the detail description of certain preferred"embodiments which follows, reference being had to the annexed sheet'of drawing in, which: i

Fig. 1 is a side elevation, in part sectional, of

the cloth cutting machine of the invention;

Fig. 2 is a cross-sectionalfview onthe line 2- 2 of Fig. lthrough the base of the machine;

Fig.3 is an enlarged cross-sectional. view on the line 3-3 of Fig. 1,. showing the position occupied by thepresserfoot relativetojthe knife;

Fig. 4 is a crossrsectionalview on the line4-,,,4-.

of Fig. 5;

Fig. 5 is an enlarged cross-sectional view of the connection between the upper end-of the knife guide and the motor chassis shown in Fig. 1;

Fig. 6 illustrates the undulating line of 'cut designed to be made by the clothoutting machine of theinvention.

'Corresponding in general with. cloth cutting machines of usual design the machine of the present'embodiment comprises a flat base plate 1, adapted to roll upon a work table, a standard 2 rising vertically from the base, and a motor chassis 3, including an electric motor 4, located above the upper end of the standard 2." The base plate 1 is of generally oval contour and isdished on itsund'er surface 'to provide a shell-like housing fortwo pairs of rollers 6 and 7. The, treads of these rollers are of. live rubber (or other'suitable composition) so as to aiford'good'ffriction contact with the surface of the work table over which the machine is adapted to be displaced.

The 'paii' of rollers 6 is fixedly mounted upon'a shaft'll'near the rear, or trailing, end of the base, this shaft extending transversely between the side walls forming the concave bottom of the base and being'journaledin bearing lugs 9 projecting from "the walls. The base plate 1, at a point slightly displaced from its geometrical center is provided with a circular opening 10 and this openingis surrounded with a downwardly directed neck 11 extending into the concavity of the bottom of thebase plate- Shafts 12, upon each of which fi's mounted a'roller 'l, are disposed in alignment with each other and in parallelismwith shaft 8 ',upon the under surface of the base. at a position 'for'wa'rdly'of the latter shaft. Each of theshafts 12 has one end journaled in a bearing 13 formed on the marginal portion of the shell andits other end received within a bearing 14 on the outer circumference of the neck.

The lower end of the neck upon its innercir 'cumference is "screw threaded and threadedly fastened within this portion is a disk 15. Rigidly attached to this disk and rising vertically therefrom at a point located slightly to the rear of 1' its center is the standard 2. The standard is of elongated cross-sectional. dimensions and, in a direction transverse of the base, is ofcomparatively small thickness. The front edge of the 7 standard for a substantial portion of its length is provided with an arcuate groove 16 (Fig. 3) defining in effect a socket in which is received a knife guide 17. The knife guide comprises a ver' tically extending rod having a convex, rear wall 18 snugly seating within the groove 16 of the standard, the arrangement being suchthat the knife guide is capable of turning about its longi tudinal axis within the groove. The convex Wall 18 merges with two side walls 16a and 1617 which converge toward the front of the knife guide.

For maintaining the knife guide in assembly with the standard 2 the lower end of the guide is provided with a generally circular throat plate 20 snugly received within the opening 10 and supported upon the disk 15 through a ball bearing In order to permit rotation 'of the throat plate 20 within the opening 10, this plate is provided with an arcuate slot 22 (Fig.2) furnishing a clearance opening for the standard 2 in different angular positions of the plate.

The knife guide has a slot 23 intersecting'the apex defined by the intersection of the two converging walls 16a and 16b, this slot extending throughout the major portion of its length and terminating at its lower end in a recess 24 formed in the throat plate 20. A fiat knife 25 having a longitudinal cutting edge 25a slides within the slot 23 of the knife guide 16, the lower end of the knife being inclined and formed with a shearing edge 251) which fits the recess 24 and defines with its slightly sloping edges 26 a throat for severing" the bottommost layers of the pile of fabrics. By reason of the construction just described the throat platefZO, oscillating in unison with the knife guide 17 always presents the recess 24 in operative position for receiving the lower shearing edge 25b of the knife. The upper end of the knife is offset as'at27 and is provided with a terminal .slot 28 arranged to receive a threaded pin 29 for clamping it to a crosshead 30 by means of a nut, not shown, threaded upon one end of the pin.

The motor chassis 3 comprises a casting 32 providing a' rigid support for the motor anda slide way 33 forthe crosshead 30, and constituting a frame to which suitable face plates 34 may be attached for housing the moving parts. The armature shaft of the electric motor 4,, mounted upon the chassis 3, is provided with a balance crank 35 which is operatively connected ,to a pin 36 extending laterally from the crosshead 30, located below the crank by means of a connecting rod 37. Consequently as the crank 35 is rotated the crosshead 30 will reciprocate Within the slideway 33 carrying with it the knife 25. Since any of the conventional mechanisms for reciprocating the knife of cloth cutting machines may be employed the above mechanism is merely suggestive and requires no further description. A switch 4a may be provided for turning on and off the current for the motor 4.

The upper end of the knife guide-'17 termihates in a block 40 (Fig. 5) and this block is "provided with a cylindrical recess 41 in axial alignment with the slotted portion of the knife guide but terminating short of the bottom of the block. The lower face of the block at its rear edge is cut away to define a groove 42 and an overhanging ledge 43.. The'bottom of the recess 41 opens laterally into. the vertical wall of the groove through a flared channel 44 as shown in Fig. 4. The block 40 is maintained in rigid assembly with themotor chassis 3 by means of bolts 45 which are threaded through vertical openings in'theledge 43 and fastened to the bottom of casting 32. It will be evident from the construction a just described that oscillation of the knife guide 17 will impart unitary turning movement to the knife blade 25, the throat plate 20 and the motor chassis 3.

top of the stem is screw threaded'to receive a nut'48. A handlebar 49 extending horizontally to the rear of the machine fits, at its inner end, over the'squared portion 4'7 of. the stem on which it is retained by the nut 48 so that in the opera tion of the machine during the oscillation of the block 40, the handle bar remains stationary with the standard. The end of the handle bar is provided with a grip 50 arranged to be grasped by the operator to move the machine over the table. In order to offset the tendency of the knife to lift the chassis 3 lengthwise of the stem 47 upon its upstroke, a thrust-bearing is interposed between the block 40 and the handle bar 49, this bearing consisting of a ball race ring 51 surrounding the stem and contained within a pocket 52 defined by complementary recesses formed in the upper face of the block 40 and the lower face of the handle bar 49. Since the opening 41in the block 40 is made slightly oversize to facilitate the assembly of the standard 2 with the block 40, the ball race ring 51 serves the addtional function of centralizing the stern within the opening. The handle bar is provided with 1 arcuate clearance slots 53 so as not to interfere with the swinging movement of the bolts 45, while the fia'redchannel 44 is of such shape as to permit oscillation of the'block.

A presser foot 55 is'bifurcated so as to receive with a minimum amount of clearance thecutting edge of the knife. The presser foot resiliently bears against the cloth in front of and upon the two sides of the knife maintaining the fabric in a flat condition and, upon the upstroke movement to the knife guide and, consequently,

to the motor chassis 3, this embodiment of the invention contemplates the provision of a pair of cams 5 6 eccentrically displaced 180 degrees upon the shaft 8 carrying the rollers 6 in the base of the machine. Each one of a pair of parallelthrust rods 57 intermediately supported and slidably received within openings formed in a lug 58 on the bottom surface of the base plate 1 has one end in rubbing contact with one of the earns 56 and its opposite end extending through an opening in the neck 11 and bearing against a fiat 59 formed upon the circumference of the throat.

These points of contact of the thrust plate 20. I rods 57 with the throat plate '20 are located equidistantlyfroinandupon opposite sides of th center of the throat plate. Whengthrefore, the shaft 8 revolves, the cams 56 acting against the ends of the thrust rods 57 alternately rock the throat plate back and forth.

In operation, the machine will be supported upon the work table upon which reposes the lay of fabrics to be cut, the uppermostlayer having previously been marked in accordance with a predetermined pattern. The motor 4 having been set in operation by means of the switch 4a to reciprocate the knife 25, the operator next grasps the grip and guides the machine over the table advancing the knife through the lay, along the guide lines marked on the top layer of cloth. As the machine rolls over the table upon the rollers 6 and '7, the shaft 8, carrying the rollers 6, is rotated, and, through the eccentrically disposed earns 56 and thrust rods 57, automatically imparts oscillating motion to the throat plate 20, the knife guide 17, the knife 25, and the motor chassis-3. foot embracing the knife 25 depends from a portion of the motor chassis, it follows the oscillations of the knife and does not interfere with its an ular movement; and the throat plate, moving in unison with the knife, always presents the recess 24 in operative position witlirespect to the lower shearing edge of the knife. As the period of oscillation is determined by the rate at which the rollers 6 rotate, and as this rotation varies directly with the rate at which the operator moves the'machine forward over the work table, the number of scallops per inch and their curvature are fixed and independent of the rate of movement of the machine; whether, fast or slow, constant or varying.

I claim:

1. In a-cloth-cutting machine, a knife and means for automatically oscillating the knife about a vertical axis, said machine being constructed and arranged for bodily displacement relative to the work, the period of oscillation varying with the relative movement of the cloth and the machine. 7 v

2. In a cloth-cutting machine of the reciprocating knife type, a base plate constructed and arranged for bodily displacement relative to the work, a knife and slotted throat plate mounted on the base plate, and means for automatically oscillating them as a unit about a vertical axis with reference to the base plate in response to movement of the machine.

3. In a cloth-cutting machine of the reciprocating knife type, a base plate constructed and arranged for bodily displacement relative to the work, a knife, a motor and slotted throat plate mounted on the base plate, and means for automatically oscillating them as a unit about a vertical axis with reference to the base plate in response to movement of the machine.

l. In a cloth-cutting machine of the reciprocating knife type, a base plate constructed and arranged for bodily displacement relative to the work, a knife, a slotted throat plate and a presser foot mounted on the base plate, and means for automatically oscillating them as a unit about a vertical axis with reference to the base plate in response to movement of the machine.

.5. In a cloth-cutting machine of the reciproeating knife type, a base plate constructed and arranged for bodily displacement relative to the Work, a knife guide, knife and slotted throat plate mounted on the base plate, and means for automatically oscillating them as a unit about a vertical axis with reference to the base plate in response to movement of the machine.

6. In a portable cloth cutting machine of the Since the presser reciprocating knife type, a vertical standard constructed and arranged for displacement relative to the work, a knife guide oscillatable about said standard, a knife reciprocable within the knife guide, means for reciprocating the knife and means for automatically.oscillating the knife guide in response to movement of the machine.

8. In a cloth-cutting machine of the reciprocating knife type, a base p1ate,'a motor, knife guide, knife, slotted throat plate and presser foot mounted on the base plate, and means for oscillating them as a unit about a vertical axis with reference to the base plate, the period of oscillation varying with the relative movement of th cloth and the machine.

9. In a portable cloth-cutting machine of the reciprocating knife type, a base plate, rollers on the base plate for supporting the machine on a work table, a motor, knife guide, slotted throat plate, and presser foot mounted on the base plate, and means actuated by the rollers for oscillating them as a unit, about a vertical axis with reference to the base plate as the machine moves over the table. 7

10. In a portable cloth-cutting machine of the reciprocating knife type, a vertical standard constructed and arranged for displacement relative to the work, a knife guide oscillatable about said standard, a knife reciprocable within the knife guida neans for reciprocating the knife, a presser foot arranged in advance of the knife for engaging the work, and means responsive to the displacement of the machine for automatically oscillating the knife guide, knife and presser foot as a unit.

11. In a portable cloth-cutting machine of the reciprocating knife type, a vertical standard, a knife guide oscillatable about saidstandard, a knife reciprocable within the knife guide, means for reciprocating the knife, a handle for displacing the machine upon a work table, and means controlled by the displacement of the machine for oscillating the knife guideQ l 12. In a portablecloth-cutting machine of the reciprocating knife type, a vertical standard, a

knife guide oscillatable about said standard, a

knife reciprocable within the knife guide, means for reciprocating. the knife, a handle for displacing the machine upon a work table, and a .roller in frictional contact with the work table for os-' guide in response to moveknife guide oscillatable about said standard, a j knife reciprocable within the knife guide, means for reciprocating the knife, a handle for displacing the machine upon a work table, a roller in frictional contact with the work table, a cam shaft rotatable by the roller, and means connecting the cam shaft and knife guide for oscil- 

